Although the present invention would find ready use on all types of motion chairs, such as reclining chairs and swivelable reclining chairs, in its simplist form the invention relates to rocking chairs which have a legrest (or footrest), which when projected from a stowed condition supports the user's legs in a feet-off-the-floor disposition.
As is well-known, when sitting in a rocking chair, most people apply cyclic foot pressure to the floor while cyclically flexing their leg muscles to bend at the ankle, knee and hip joints in order to rock. But when the rocking chair has a projectable legrest or footrest, and the user projects it, thus sweeping their feet up off the floor, something must be done to block the rockability of the chair. Otherwise, many the user will experience a distinctly uncomfortable out-of-control feeling: he or she no longer can regulate rocking by applying cyclic foot pressure to the floor and minor shifts in the user's position on the chair may set up an uncontrolled extreme-to-opposite-extreme tilting motion which would readily be perceived by many as signalling that the chair is about to tip over.
In order to avoid the possibility of giving the chair user such an untoward experience, motion chair manufacturers have devised diverse ways and means for preventing their chairs from rocking once the user's feet are off the floor. Some of these work quite well on one model or type of chair, but are not useful on others; some are not durable, or require undue precision in manufacture and installation, more than is feasible in a mass manufacture situation.